Currently available are a number of mechanical fittings which allow the joining together of two or more pipes or tubes through the application of mechanical force. The pipe fitting generally involves the deformation of a portion of the tube or pipe and a portion of the fitting itself when mechanical force is applied. A successful example of a tube fitting is described in U.S. Pat. No. 4,482,174 issued on Nov. 13, 1984 and entitled "APPARATUS AND METHOD FOR MAKING A TUBE CONNECTION," which patent is under license to the present assignee and which patent is incorporated herein by reference. This patent describes a tube fitting for joining two tubes together which include a coupling body having an inner cylindrical surface and an outer cylindrical surface and first and second swage rings. The swage rings can be mechanically urged over the outer surface of the coupling body from the first and second ends, respectively, of the coupling body. The two tubes to be joined are inserted into the first and second ends of the coupling body, respectively. The inner surface of the coupling body includes one or more teeth which are urged into engagement with the tubes in order to provide a mechanical seal. The outer surface of the coupling body includes protrusions. When the swage rings are urged over the coupling body, the swage rings force the protrusion inwardly causing the teeth to be urged into biting engagement with the pipe creating the above mechanical seal and connection. Such devices use one or more teeth and/or protrusions.
While the above fitting has proved to be highly successful, improvements have been developed which enhance the mechanical sealing and connection function.